| 摘要: |
| 为探究根施甜菜碱与调控叶片光合、抗氧化能力和渗透调节的关联，以及对增强甜瓜幼苗耐盐的可行性，以‘西州密25号’甜瓜幼苗为试验材料，采用水培根灌甜菜碱的方法，将甜瓜幼苗用不同浓度甜菜碱（5、10、20和40 mmol/L）预处理3 d，再用NaCl胁迫（75和150 mmol/L）处理7 d后，测定甜瓜幼苗根系活力、细胞膜相对透性、光合色素、光合生理、渗透调节物质以及抗氧化酶活性等指标。结果表明：1）与对照组相比，不同浓度NaCl对甜瓜幼苗的各项生理指标影响差异显著（P<0.05）。2）根施甜菜碱预处理对NaCl胁迫有一定的缓解作用，5~10 mmol/L的甜菜碱可不同程度地提高甜瓜幼苗叶片中光合色素含量、光合能力及抗氧化酶活性，缓解效果最佳。3）5~10 mmol/L甜菜碱预处理的甜瓜幼苗根系活力、光合特征参数在150 mmol/L NaCl胁迫下比在75 mmol/L胁迫下低，说明根施甜菜碱缓解低浓度NaCl胁迫的效果更优。综上，外施甜菜碱预处理通过调节多种生理生化机制，能有效缓解甜瓜幼苗受到的盐害，使甜瓜幼苗能够抵御NaCl胁迫，且以浓度为5~10 mmol/L缓解效果最佳。 |
| 关键词: 甜瓜 甜菜碱 NaCl胁迫 光合作用 渗透调节 抗氧化酶活性 |
| DOI：10.11841/j.issn.1007-4333.2024.03.09 |
| 投稿时间：2023-05-10 |
| 基金项目:新疆维吾尔自治区人力资源与社会保障厅高层次人才引进工程项目（2017-2020）；自治区自然科学基金计划——特培项目（2019D03016）；新疆维吾尔自治区“天山创新团队计划”项目（2021D14009） |
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| Alleviating effect of root application of betaine on muskmelon seedlings under NaCl stress |
|
JIANG Yan1, GULIZIYE Halike2, QIN Qian1, AILIJIANG Maimaiti3*
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| (1.College of Horticulture, Xinjiang Agricultural University, Urumqi 830052, China;2.Institute of Grape and Muskmelon of Xinjiang Uygur Autonomous Region, Shanshan 838200, China;3.College of Life Sciences, Xinjiang Agricultural University, Urumqi 830052, China) |
| Abstract: |
| In order to explore the relationship between betaine root application and regulating leaf photosynthesis， antioxidant capacity and osmotic regulation， and the feasibility of enhancing salt tolerance of melon seedlings， ‘Xizhoumi 25’ melon seedlings were used as study materials. Muskmelon seedlings were pretreated with betaine （5，10，20 and 40 mmol/L） for 3 days， and then treated with NaCl stress （75 and 150 mmol/L） for 7 days. The root activity， relative permeability of cell membrane， photosynthetic pigment， photosynthetic physiology， osmotic adjustment substance and antioxidant enzyme activity of muskmelon seedlings were determined. The results showed that： 1） Compared with the control group， different concentrations of NaCl had a significant impact on various physiological indicators of melon seedlings（P<0.05）. 2） Root application of betaine pretreatment had a certain alleviating effect on NaCl stress. Betaine with a concentration of 5-10 mmol/L can improve the content of photosynthetic pigment， photosynthetic capacity and antioxidant enzyme activity in the leaves of melon seedlings to varying degrees， with the best mitigation effect. 3）The root activity and photosynthetic characteristic parameters of melon seedlings pretreated with 5-10 mmol/L betaine were lower under 150 mmol/L NaCl stress than under 75 mmol/L NaCl stress， indicating that root application of betaine had a better effect in alleviating low concentration NaCl stress. In conclusion， exogenous root application of betaine can effectively alleviate the salt injury to muskmelon seedlings by regulating various physiological and biochemical mechanisms， enabling them to resisit NaCl stress. The best mitigation effect was at the concentration of 5-10 mmol/L. |
| Key words: muskmelon betaine NaCl stress photosynthesis osmoregulation antioxidant enzyme activity |
